Bug FAQWestern Pine Elfin
Incisalia eryphon · Order: Lepidoptera · Family: Lycaenidae
Source: Wikipedia
The western pine elfin is a small butterfly about 19 to 32 mm long with no tail and bold patterned hind wings; males are brown and females orange-brown, and the wing tops have dark bars and a lighter chevron margin. It lives in pine woods and evergreen forests of the western United States, especially lodgepole pines, where its larvae feed on young pine needles and can cause defoliation.
Source: Wikipedia
How to recognize it
Males are brown and females orange-brown, both with bold patterned hind wings and dark bars topped by a lighter chevron on the wing edges.
Source: Wikipedia
Size
Adults measure 19 to 32 mm in length and lack a tail.
Source: Wikipedia
What it eats
Adults sip nectar from wild blueberries, milkweed and clover, while larvae eat the young needles of pine trees.
Source: Wikipedia
Life cycle
Adults emerge in early spring (March-June), lay eggs on new pine needles, and produce one brood; larvae grow to about 15 mm, are green with cream-yellow stripes, and hibernate before pupating.
Source: Wikipedia
When you see it
The single flight period occurs from March to June.
Source: Wikipedia
Where it is found in the US
Recorded in 25 of 51 states and DC. Most records: California, Colorado, Oregon, Idaho, Washington, Wyoming, Montana, Arizona.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Months it is reported in the US
Source: GBIF
Questions people ask
How does the western pine elfin damage trees?
Its larvae feed on the new pine needles, stripping them and causing defoliation.
Source: Wikipedia
When can I see adult western pine elfins?
Adults are on the wing from March through June.
Source: Wikipedia
What do the caterpillars look like?
Mature larvae are about 15 mm long, green with a velvet texture, cream-to-yellow stripes, and a green head.
Source: Wikipedia
Same family (Lycaenidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Western_pine_elfin
Look it up elsewhere: GBIF · iNaturalist · BugGuide · Wikipedia
Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-23.